@tig said:

Sounds like he modeled the surface in 3d in CAD but drew/imported the carpark layout flat in 2d at z=0.
So moving them up will mess up if they are all flat and the surface is 3d.
A solution to this would be to group all of these carpark lines and then move the group vertically [as Gaieus explained]... but so that they end up well ABOVE the surface... then use the Sandbox tool's Drape function to make a set of lines drawn over the 3d surface - the 'flat' grouped set can then be erased, or put onto its own 'off' layer...

Thanks Guys - worked a treat. (original file created in AutoCAD with over 250 layers - there is a lot of extraneous data "floating" around which is slowly being deleted to get the file down to a manageable size).
Cheers and Thanks
Max